In conventional commercial broadcasting facilities, a singer and an orchestra typically are recorded in stereo on a single recording medium, such as a rotatable disk or a magnetic tape. The singer is typically in the same room as the orchestra and the microphone or microphones which sense the audio signals from the orchestra also simultaneously sense the audio signals emanating from the singer although the singer has an individual microphone nearby. The resulting recording provides a reproduction of the combined audio output of the orchestra and the singer, but the singer's output cannot be isolated from the orchestra output and vice versa. Moreover, the singer's output cannot be adjusted in volume without affecting the volume of the output of the orchestra. Thus, the type and quality of the recording which is capable of being achieved with commercial systems is limited and cannot provide the versatility which would make recording media much more widely usable in entertainment and in educational applications. A need has, therefore, arisen for an improved audio recording technique which can achieve this aim without materially increasing capital investment and studio equipment costs.
Applicable prior art in audio recording includes the following U.S. Pat. Nos. 1,765,735; 2,519,103 and 3,843,137.